1. Field of Invention
The present invention relates to a power supply module. More particularly, the present invention relates to a motherboard power supply module.
2. Description of Related Art
Generally speaking, a conventional switching power supply module includes an input rectification circuit, an input filter circuit, a dc converter, an output filtering circuit, and a pulse width modulation circuit. The input rectification circuit and the input filter circuit rectifies and filters an ac input current into a rough dc current, then the rough dc current is converted to a rough square wave. After that, the voltage level of the converted square wave is tuned to the required level, and the output filtering circuit generates a more precise output dc current accordingly.
Because the power signal provided by the power supply module needs to be stable, the power signal is continuously checked to make sure it is stable. For this reason, the power signal is returned to the controller of the power supply module, checked by the controller and tuned accordingly. To tune the power signal, the controller usually includes a pulse width modulation circuit, which compares the power signal and a reference signal, and tunes the duty cycle of the pulse width modulation signal, which controls the volume of the power signal.
However, in order to detect the power signal, the conventional power supply module usually requires numerous voltage feedback wires connected to the controller, which makes the wires located on the motherboard more complicated, and the production period of the motherboard becomes longer as a result. Besides, a larger motherboard is required to accommodate the numerous wires, which makes this kind of motherboard incompatible with small electronic devices.
Therefore, there is a need for a new power supply module with a simplified feedback wire structure and a smaller circuit area.